At present, when sending uplink data, a terminal first needs to obtain, through a random access process, a time-frequency resource for sending the uplink data, that is, after achieving uplink synchronization, the terminal starts to send the uplink data by using the time-frequency resource.
However, when the existing method is used, if uplink data sent by the terminal is a small data packet, the random access process needs to be performed each time before a small data packet is sent, which leads to a delay in transmission time. Besides, because the random access process generally requires exchange of a dozen pieces of signaling, that is, overheads of a dozen pieces of signaling are occupied each time a small data packet is sent, transmission efficiency is low.